A new Intel Itanium (IA-64) emulator that boots Windows

https://raymii.org/s/blog/Intel_Itanium_IA-64-Emulator_that_boots_Windows.html

by jandeboevrie • 3 days ago

84 70 3 days ago

cbmuser• 3 days ago

What's even crazier is that someone vibe-coded ia64 emulation support for QEMU: https://github.com/syunnPC/qemu-system-ia64

userbinator2• 3 days ago

It's interesting to see how LLMs have definitely become a force-multiplier to motivate people into doing things they wouldn't otherwise have the time and effort to.

rbanffy5• 3 days ago

I have been pairing with Claude Opus and it’s quite impressive. I have explored a number of possible changes to things like VTE and the Hercules mainframe emulator.

qubex3• 3 days ago

Open Source and LLMs seem to be complementary technologies that have resulted in an absolute surge of productivity multipliers.

pizza234• 3 days ago

It really depends on the end goal. For personal tools that one uses, LLMs are extremely useful. But publicly used software doesn't only need to be written - it also needs to be maintained. And considering that it's extremely easy to implement features that are not used, vibe coded software tends to be, in best case, a mixed bag, and in worst (I believe typical) case, quickly abandoned.

Vibe coded software is the modern equivalent of the shovelware of the 90s.

ColdStream2• 3 days ago

Recently thanks to Modern Vintage Gamer on youtube, there has been a push to see if you could get Doom to run on the NeoGeo. Because of its very unique hardware (no framebuffer) it is a very unqiue and tough task.

And yet, some folks have come to the battle and have ended up extensively using LLM's to code it. It is wild to see that these things can target such an obscure platform and get some decent results in a very short amount of time.

https://www.youtube.com/watch?v=WPxhuKTltsk

This is something that doesn't have any real economic value but many are more than happy to see happen.

monster_truck• 3 days ago

In this domain and others like it especially!

It's bone crushingly dry to try and figure this kind of shit out yourself, can do everything right according to every available reference and code comment only to get compiler and linker errors nobody has ever seen or posted about. Weeks and weeks of smashing your face against a wall until it gives. Now anyone can get twice as far in an evening. And that fuckin rules

Hard to not get a little hyperbolic about it... but I can't wait for everyone to exhaust their meme projects/ports and models to get just a bit better. Feels like we're about to have something of a golden age when everyone starts really making the stuff they've always wanted.

natas4• 3 days ago

I wish this could make it to qemu's main branch; always fun to preserve new systems. I wonder if it runs openvms/ia64 too!

rbanffy5• 3 days ago

I think most of the machines that could run Windows could also run OpenVMS. It’s a bit unfortunate the company behind the OS needs to make money off its licenses though.

ChickeNES• 3 days ago

Well, that's one vibe coded backburner'd project I can mark off my list...though maybe it would still be helpful so I'll link it here: https://github.com/ChickenParts/qemu-ia64

It booted Linux fine, was working on booting IPF EFI firmware when I got distracted by life and other projects.

qubex3• 3 days ago

“It runs quite slowly, (486-levels of performance on a Ryzen 5000 series according to this discord channel)”

I’m sure there’s a joke about that being a huge leap in performance for Windows on IA-64 over the past 23 years waiting to be made from this.

Joel_Mckay6• 3 days ago

To be fair, most of ia64 performance issues were in the more complicated compilers. The chip itself had potential, but essentially abandoned the DOS/Windows market inertia. =3

qubex3• 3 days ago

Yeah EPIC pushed too much effort onto compilers and removed the context awareness of out of order reordering etc and the result was just a lame duck.

bri3d4• 3 days ago

No (sorry, I post this every time the Mythical Compiler Myth reappears), the problem with VLIW is that it fundamentally doesn’t work for anything with unpredictable memory access patterns, and modern general purpose computing has moved almost exclusively in this direction. For VLIW to work, you need to either guess correctly what is in cache or not have a cache at all; as soon as you mispredict what has been loaded, you stall while an OoO processor keeps going and a speculative OoO processor even keeps guessing. With multiple workloads on the same hardware (virtualization, multitasking, multitenancy) this becomes an intractable problem even in the presence of the magic compiler which can solve for software based unpredictability (branch likelihood and pointer chasing), because every context switch clobbers an unknown set of cache lines and blows the entire thing up.

VLIW works for single workloads. It works exceptionally well for single workloads with no or explicit cache like DSP. You can trade the footprint and complexity from OoO for a wider execution unit and more SRAM. It works well for HPC, too, for the same reason. But for anything where more than one process exists, it just really doesn’t work, and that’s most modern workload.

Itanium also has a unique set of self inflicted issues due in large part to Intel trying to make a wide variety of cross compatible parts, but IMO even if they’d got it right, it still would have died.

ColdStream2• 3 days ago

Itanium is yet another example of how difficult it is to fight software ecosystem momentum.

It had potential but until you have an easy transition path, few will consider it. Apple figured that out during the 68K > PPC > X86 > ARM transitions.

mixmastamyk• 3 days ago

Neat I did this on real hardware twenty plus years ago. Also tried Debian, iirc. My memory is that the workstation perf was decent but the thing was loud and used a lot of power. x86 emulation was slow. The nick, Itanic was mostly deserved.

Joel_Mckay6• 3 days ago

The ia64 more complex compiler ecosystem made it difficult or impossible to port performant programs to the platform. Amd64 allowed people to keep building and running most programs with little understanding of what was happening in the architectural layers.

Even the 800lb guerilla Intel had to acknowledge amd64 was the next step, or it could end up a niche use chip like PowerPC.

The moral of the story is usability matters with consumer chip architecture. =3

lorreyfum2• 3 days ago

The Itanic was built specifically by HP to sink Fujitsu, hitachi, nec, unisys and sgi. So in that sense it was a success.

butterisgood2• 3 days ago

True. But it’s a technological representation of all that’s wrong with the industry.

lorreyfum2• 3 days ago

Absolutely. This monstrosity managed to have all what was wrong with CISC and all of the disadvantages of RISC at a higher price point than anything on the market at the time.

kstrauser• 3 days ago

This was my take on it: https://honeypot.net/2021/07/29/the-itanic-has.html

Key relevant quote:

In 1994, Intel and HP looked around and saw a wide variety of successful server CPU architectures like Alpha, MIPS, SPARC, and POWER. This annoyed them and they decided to make a new CPU that no one would want to use.

butterisgood2• 3 days ago

When it comes to Itanium all I can think of is how I wish I could have an Alpha. And how no one should care about Itanium.

It’s the product of companies bent on doing all the wrong things.

twoodfin• 3 days ago

It took longer than necessary, but in what ways do you think an Intel Core-derived chip is different from what an “Intel Alpha” would have been?

Taking for granted that hardware backcompat (Itanium had this, too!) was a starting requirement…

speed_spread• 3 days ago

Alpha was great but that wasn't enough against the convenience of just running an x86 box. It didn't find a niche quickly enough. ARM survived because they were low power. POWER survived because IBM is one big niche. MIPS died and reincarnated into RISC-V. I have no idea where Alpha would have gone had it not been dropped.

MarekKnapek• 3 days ago

Wasn't there a problem with Alpha, that it had too weak memory model or something? Think of atomic instructions with multi CPU system. Or do I remember something wrong?

djhope992• 3 days ago

I have a funny story about a windows IA-64 box.

I was working for a large bank and it was all windows, including production. We used to run WebSphere Application Server on Windows. I was looking for a dev server to run unit tests on, including integration tests which required an actual WebSphere instance. The infrastructure team said they had “a box” going spare and it turned out to be IA64 on Windows.

If my memory serves me correctly WebSphere only ran on windows for IA-64 up to 6 and we were running on 7.

I had to do a bit of hacking but I did manage to get it working using the dlls from the 6 version. It was fine for running integration tests and a pretty fast box considering.

shoo• 3 days ago

Am I right to guess that neither your dev nor prod machines ran IA-64? If so that's not ideal, but beggars can't be choosers & a spare box from the infra team available right now is better than getting a box built to meet your exact specs available after the usual multi-quarter internal lead time.

Superficially it sounds a little crazy, but it's probably a lot less crazy than far more mainstream antipatterns (e.g. 'lets have our CI download all the dependencies from npm over the internet each time the build runs')!

Did running the unit tests on IA-64 ever flush out genuine issues that were 'working by accident' on x86?

djhope992• 2 days ago

If so that's not ideal

Agreed!!

I would have loved something better but sometimes you just have to make do.

WebSphere was 99% Java (except for a few pesky dlls) and I never saw any oddities, it worked the same as it did on the old x86 VM I had which was woefully under spec. Our entire software platform was on WebSphere.

It really was a meaty box, which was a huge help because the tests originally (before IA64 box) used to take all night to run.

itomato• 3 days ago

HP-UX support might make a compelling retirement project for someone.

natas4• 3 days ago

For sure, I'm glad we have those emulators, real hardware is hard to find or expensive or faulty. Having emulators helps a lot.

pjmlp4• 3 days ago

C and C++ compilers weren't great, but that HP-UX Vault was a great experience, before anyone knew what the word containers in computing world means.

shrubble• 3 days ago

OpenVMS ran on the Itanium also; wonder how far it could get in booting?

xvilka• 3 days ago

It would make sense to implement it in QEMU instead. There was some previous work in the past, don't have a link right now to the original patchseries, but here is the repository[1]. In theory, it could be adapted to the modern QEMU code infrastructure and APIs and be a good starting point. Back in the past I started[2] doing that but quickly dropped because had no time to finish.

EDIT: It looks like it might be this one: https://github.com/syunnPC/qemu-system-ia64

[1] https://github.com/pvaibhav/qemu-ia64

[2] https://github.com/XVilka/qemu-ia64/branches/all

kiaansaraiya• 2 days ago

This is much harder problem than most CPU emulators as IA-64 isn't really just another ISA. EPIC most significantly allows the RE which seems like the main implementation challenge. Does the emulator model the RSE or are there shortcuts for Windows compatibility? Also, which Windows model is booting?

A new Intel Itanium (IA-64) emulator that boots Windows

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